Expansion valve



5 1969 R. GrzENar-:RGER 3,459,211

EXPANSION VALVE med sept. 21. 1967 s sheets-sneer 2 Inventor:

Pudl'bert Gfzenbeger by /Vo/e if /Vale A'Horneys Aug. 5, 1969 R. GTZENBERGER 3,459,211

EXPANSION VALVE Filed sqpt. 21.11967 s sheets-sheet s Inventor: Pad/'bert Gzen berger by /VoH-e Volte AHorneyg United States Patent O int. ci. ms 31/165 U.S. Cl. 137-270 S Claims ABSTRACT F THE DISCLGSURE An expansion valve for refrigeration and cooling systems whlch can be used selectively in systems with a relatively large as well as a relatively small evaporator output by being provided with a valve body having two passages respectively leading to passages that can be connected to the inlet or outlet of an evaporator. One or the other passages can be selectively closed by a plunger made effective by a simple reversal of an insert in the valve.

Background of the invention The present invention relates to an expansion valve system with a valve controlled by a diaphragm which is on one side subjected to the pressure prevailing in a temperature sensor arranged at the outlet of an evaporator. More specifically, the invention is concerned with an expansion valve system of this type which may be employed in evaporator systems of relatively high and also relatively low output.

The operation of thermostatically controlled expansion valves is on one hand determined by the control pressure prevailing in the temperature sensor of the valve and acting on one side of the diaphragm and, on the other hand, depends on the pressure prevailing on the opposite side of the diaphragm. The temperature sensor is provided at the outlet of the evaporator at the suction pipe thereof in such a way that good heat conducting conditions exist so that it is continuously at the temperature of the cooling gas leaving the evaporator.

Whereas, with systems having a relatively small evaporator output, the diaphragm chamber on the valve side of the diaphragm is directly connected with the passage or conduit in the valve body, which leads to the evaporator, with systems of larger evaporator output, the diaphragm chamber on the valve side has to be connected to the outlet of the evaporator, in view of the pressure losses occurring in such evaporators. Therefore, in the heretofore known refrigerator systems different expansion valves were used in systems with a relatively small evaporator output than in systems with a relatively large evaporator output.

It is, therefore, an object of the present invention to provide an expansion valve which can be used with evaporator systems having a relatively large output as well as with evaporator systems having a relatively small output.

The invention is illustrated by way of example in the accompanying drawing in which:

FIG. 1 illustrates a longitudinal section through an expansion valve designed in conformity with the present invention;

FIG. 2 is a top view of the expansion valve of FIG. 1, with parts omitted and with other parts broken away, the valve being shown in a iirst operative position;

FIG. 3 is a section similar to that of FIG. 1 but taken along the line 3-3 of FIG. 4;

FIG. 4 is a top view similar to that of FIG. 2, but showing the valve in a second operative position; and

Frice FIG. 5 shows on a larger scale than FIG. 4, a portion of FIG. 4.

In order to be able to employ the same expansion valve for refrigeration or cooling systems of different and varying evaporator output, the expansion valve according to the present invention is provided with two bores which may be selectively closed or blocked. One of these bores connects the chamber on that side of the diaphragm which is opposite to the one subjected to the pressure prevailing in the temperature sensor to the passage leading directly to the evaporator, whereas the other bore connects this chamber with a conduit leading to the outlet of the evaporator.

More specifically, the expansion valve has a housing with a first chamber for connection with the temperature sensor of an evaporator and a second chamber, a diaphragm separating said two chambers, and a valve with a valve stem operated by the movement of the diaphragm. A first and a second passage for respective communication with the inlet and outlet of an evaporator, and a third and a fourth passage respectively leading from the second chamber to the first and second passage are provided in the valve. The third and fourth passage are selectively blocked by a plunger which is held in the respective blocking position by the reversible insert. In this way, in one position of the plunger, the second chamber is connected with the third passage and in the other position with the fourth passage.

Description of a preferred embodiment Referring now to the drawing in detail, FIGS. 1 and 3 show a longitudinal section through the expansion valve according to the present invention. The valve comprises a valve body, generally designated with the reference character V, with a cup-shaped portion 4 receiving a central member 2 with a valve body 2a and a spring 2b urging valve body 2a towards a valve seat 1. Portion 4 has a bottom 4a which forms one end face of a diaphragm assembly 5 and is also provided with a bore 4b for receiving a valve stem 3 connected to a diaphragm 6. The valve body also comprises an extension 7 with a passage 7a leading to an evaporator (not shown).

In the wall portion 4c of cup-shaped portion 4, which faces the extension 7, two parallel bores 8 and 9 are provided which communicate with a passage 10. MoreY specifically, the irst bore or passage 8 connects the chamber 5b of the diaphragm system 5 with the passage 7a leading to the evaporator. The second bore or passage 9 is arranged at an angle with regard to a line connecting,

be described further below. Passage 10- is arranged tan-rgentially to the wall portion 4c of the cup-shaped body 4 and receives a coil spring 11 which rests against one end face of a piston 12 displaceably arranged in passage 10. Piston 12 is adapted to selectively close one or the other of passages 8 and 9.

Piston 12 subjected to the force of spring 11 is held in one or the other of its two end positions, in which it closes either passage 8 or passage 9, by an insert 13 resting against the other end face of piston 12. As is more clearly shown in FIG. 5, insert 13 is inserted in a sleeve 14 of valve body V and is held in ixed position and received by a nut 15. A passage 16 leading to the evaporator outlet is connected with the insert 13. Insert l13 is equipped with an axial bore 17 and an inclined radial bore 18 through which the evaporator outlet communicates via a passage 18a with passage 9` leading to chamber 5b. Insert 13 is provided with an annular flange 19` which is not arranged in the center of insert 13 but has a larger spacing from one end face 13a than from the other end face 13b thereof. For purposes of reversing the valve, it is merely necessary to separate conduit 16 from insert 13, to reverse insert 13 and insert the same again into passage 10 so that it rests against an annular shoulder 20 and is held in this position by nut 15. ln this way, piston 12 is displaced to the position shown in FIG. 2 in which pasage 9 is blocked and in which there exists a connection between the passage 8 and the conduit 7a leading to the evaporator. Incidentally, the temperature sensor 21 is connected to the diaphragm system and leads into chamber 5c thereof located above diaphragm 6.

What is claimed is:

1. In an expansion valve having a housing with a iirst chamber to be operatively connected to a temperature sensor of an evaporator and with a second chamber, a diaphragm separating said two chambers, and a valve with a valve stem operated by the movement of the diaphragm, the improvement comprising: a iirst and a second passage for respective connection to the inlet and outlet of an evaporator, a third and fourth passage respectively leading from said second chamber to said first and second passage, and means for selectively blocking one of said third and fourth passages.

2. An expansion valve according to claim 1, wherein said third and fourth passages are arranged substantially parallel to said stem and spaced from each other, a fifth passage in said housing extending transversely to said third and fourth passages, said blocking means including a plunger displaceably arranged in said fifth passage, and

also including means for selectively holding said plunger in a first position closing said third passage and in a second position closing said fourth passage.

3. An expansion valve according to claim 2, which includes an insert in said fifth passage for engagement with one end of said plunger, and a spring in said fth passage continuously urging said plunger against said insert, said insert having a sufcient length to hold said plunger selectively in one of said positions.

fr. An expansion valve according to claim 3, wherein said insert has a passage for establishing communication between the outlet of an evaporator and said second passage.

5. An expansion valve according to claim 3 wherein said fifth passage is provided with an abutment, and wherein said insert is an elongated rod provided with a ange spaced a greater distance from one end of said rod than from the other so that when said abutment is engaged by said frange in one position of said rod, said plunger closes said third passage and in the other position said fourth passage.

References Cited UNITED STATES PATENTS 2,702,703 2/1955 MacDougall 297-3 3,021,865 2/1962 Beckett 137-270 M. CARY NELSON, Primary Examiner R. I. MILLER, Assistant Examiner 

